I usually seem to end up camping at Gwern Gof Isaf farm on the A5. About a fiver a night. It has washing up sinks and a few bogs in sheds, and showers for 50p a go. Does the job pretty well really, can't complain about the price, and it's in a lovely setting.

In reply to mrjobs: Just stayed at snowdonia parc campsite , ok toilets , better ones over the railway line (whelsh highland line , not mainline!)
Micro brewery pub on site which did good food and beer was ace.